This invention pertains to a form, fill and seal machine for packaging flowable product. More particularly, the invention relates to a form, fill and seal machine for packaging flowable product, such as liquid food, that utilizes a cavity in which the packages are supported and transported packages through the machine.
Paperboard-based containers are in widespread use for the packaging of, for example, liquid food products. Examples of liquid food products that can be packaged in paperboard containers include milk, juice and the like. Such containers are also used for packaging other flowable products, such as soups that can be in a powdered or liquid form with or without particulate matter.
In conventional form, fill and seal machines, a plurality of carton blanks are stored in a flat form in a magazine. The blanks are dispensed to a carton forming station where the cartons are erected, bottom sealed, filled and top sealed. In this process, the cartons can also be sterilized, for example, after bottom sealing, prior to filling. The cartons are conveyed in an indexed manner through the various stations and subsequently discharged from the machine at an off-loading station. Generally, the cartons are conveyed through the machine by a belt or like conveying device. The cartons are supported from their respective bottoms which rest on a low friction, stationary table top-like portion of the machine associated with the conveyor.
At the carton forming station, individual carton blanks are erected and subsequently placed on one of a plurality of mandrels that is positioned on a rotating, indexed hub. At a first station, the cartons are erected and placed on the mandrel. The mandrel hub or wheel is rotated to subsequent stations to pre-fold the bottom panels, heat the panels and the seal the panels to one another to form the sealed carton bottom. The cartons are then ejected from the mandrel onto the conveyor portion of the machine for subsequent sterilization, filling and top sealing. The hubs typically include from four to six mandrels.
The mandrels provide a form around which the carton is folded and sealed. As such, each mandrel includes an elongated body that is fully fitted within the interior of the erected or semi-erected carton. The mandrel is configured so that the carton side panels rest on the sides of the mandrel and the carton bottom panels are folded around a corresponding xe2x80x9cbottomxe2x80x9d portion of the mandrel which provides structure for carton formation. The mandrel is further configured to assure that the panels fold at the score lines. In this manner, the panels are properly folded along the score lines without inadvertent collapse of adjacent portions of carton panels, e.g., collapse of adjacent side panels.
Although such mandrel-type carton forming stations work well for their intended purpose or purposes, there may well be some drawbacks when used in certain arrangements. First, these mandrel-type arrangements can be quite costly to manufacture. To promote the standards necessary in such a highly sanitary environment, the mandrels are formed from stainless steel. Often, the material used to form the mandrel is an unconventional or even exotic steel material to minimize to the greatest extent possible and even eliminate the potential for corrosion of the machine parts and contamination of the product. In addition, these parts are necessarily highly machined components, again adding to the overall cost of the packaging machine.
Second, because of the nature of the mandrel arrangement, a particular operation can be carried out only one carton at a time. That is, only one carton can have its bottom flaps in-folded, while one different carton can have its bottom flaps heated, while still one other carton can have its bottom flaps sealed. The result is that only one carton can be operated on (e.g., erected, prefolded and/or folded, heated or sealed) at a given station at a given time. This can, of course, be increased through the use of multiple mandrels and higher machine operating speeds, however, at increased cost.
In addition, during carton formation, the mandrel is disposed within the interior of the carton as the carton moves along and through the various steps at the carton forming station. That is, the mandrel remains within the interior portion of the carton as the bottom flaps are in-folded and sealed to one another. As a result, the time duration that could otherwise be used for carrying out functions on the interior portion of the carton are subsumed by that period of time during which the mandrel is positioned within the carton interior. To this end, it would otherwise be desirable to reduce or eliminate the time during which the mandrel is disposed within the carton interior so that that time period can be used for, for example, additional carton sterilization.
In addition, it has been observed that in order to economically package these food and other products, a minimum machine xe2x80x9cthroughputxe2x80x9d must be maintained. That is, the machine must be operated at a speed necessary to assure that a minimum number of packages are processed or filled in any given average period of time. This minimum throughput has increased, necessitating increased machine operating speeds and efficiency, again adding to the overall cost of the form, fill and seal packaging machine.
Accordingly, there exists a need for a high speed form, fill and seal packaging machine that minimally contacts the inside surfaces of a carton formed, filled and sealed therein. Desirably, such a packaging machine permits forming, filling and sealing multiple cartons at a time, at a throughput at least as great as known machines, and most desirably, at a slower machine operating speed.
A form, fill and seal packaging machine is adapted to receive a carton blank, erect the carton blank into an open-top carton, fill and seal the open-top carton. The cartons each have a predetermined cross-sectional shape and size.
The machine includes a frame, a plurality of stations carried by the frame including a carton erection station, a bottom flap sealing station, a filling station and a top flap sealing station, and a drive assembly. A conveying assembly is operably connected to the drive assembly for moving the cartons through the stations.
A plurality of cavity bars are carried by the conveying assembly. Each of the cavity bars defines at least one cavity formed therein corresponding generally to the cross-sectional size and shape of the cartons. Each of the cavities is defined by internal peripheral surfaces. Preferably, each of the cavity surfaces has a plurality of vacuum openings formed therein. The cavity bars are adapted to engage a carton disposed in the cavity and can secure the carton to the internal peripheral walls. In a preferred embodiment the cartons are secured to the internal peripheral walls by application of a vacuum through the vacuum openings.
Preferably, the vacuum is applied to the cartons at at least one of the stations to secure the carton within the cavity. In a current embodiment, the machine includes a top flap pre-folding station and a bottom flap pre-folding -station, and the vacuum is applied at at least the top flap and bottom flap pre-folding stations.
Preferably, the cavity bar is formed having channels formed in upper and lower surfaces thereof, and the cavity bar includes upper and lower collar portions fitted within a respective each of the channels. The collar portions can define a vacuum channel for communicating the vacuum from a vacuum source to the carton. The vacuum channels can include peripheral portions and a plurality of vacuum legs extending from the peripheral portions to openings in the collar portions. The cavity bars can be configured having a body having the channels formed therein and openings or dimples in the body corresponding to the openings in the collar portion.
Most preferably, the upper collar portions each include a vacuum port formed therein for communicating the vacuum from the vacuum source to the upper collar vacuum openings. A bore in the cavity bar body provides for communicating the vacuum to the lower collar portion. In a most preferred embodiment, each of the cavities includes an open area formed in each of the corners, traversing through the upper collar, the cavity bar body and the lower collar. The open corners are configured to allow expansion or mild deformation of the cartons as the vacuum is applied to the cartons, and also facilitates ready initial insertion of the cartons into the cavities.
In a presently preferred embodiment, the form, fill and seal packaging machine conveying assembly has a predetermined path having an upper, generally horizontal path portion and a lower path portion, and wherein the lower path portion is spaced from the upper path portion. The conveying assembly is configured having a generally vertical path portion such that a partially-formed carton is urged into the cavity as the cavity bar traverses along the generally vertical path portion.
These and other features and advantages of the present invention will be apparent from the following detailed description, the accompanying drawings, and the appended claims.